(1) Field of the Invention
The invention relates to a quantitatively controlled drug delivery device having a drug-can that can be assembled and replaced so that the continuous or single-time minor quantitative injection of the used drug can be selected.
(2) Description of the Prior Art
There are many devices for the cosmetic and medical needleless injection and microscopic treatment, and the frequently seen injector almost has a gun-shaped body having a chamber for loading the drug or other substances. The chamber is connected to a high-pressure gas. According to the high-pressure principle, the injector is pressed on the skin of the patient. When a trigger is pushed, the drug liquid is rapidly injected from a muzzle in an atomized manner.
This injector has the convenience in use and the utility, and is thus accepted by the masses. However, its structure design still has some drawbacks to be improved.
First, the power source of the injector for injecting the liquid in the atomized manner depends on the pressure of the high-pressure gas. When the external gas pressure is coupled to the injector, the adjustment has to be made manually. If the set pressure is not uniform, the spraying effect is not good. When no external gas pressure is coupled to the injector, the stability of the gas pressure control depends on the human's hand control. So, the spraying effect is not good because the applied force is not uniform.
Second, the injector usually cannot be disassembled, and the user cannot disassemble it to perform the cleaning and maintaining works. Especially, the simple failure elimination cannot be achieved by the user.
Third, the drug cannot be conveniently filled, or the drug bottle cannot be conveniently installed and replaced in some injectors, and the process is time-consuming and labor-consuming. In addition, when the drug is injected, the residual drug liquid is often left in the bottle, so that the injection amount of the drug is not precise, and the effect is naturally affected.
Fourth, the typical injector only can input the drug according to a single method set by the manufacturer, so that the flexibility and convenience in use are naturally limited.
The factors mentioned hereinabove have proved that the existing needleless injector still has to be improved.
In view of the associated problems induced by the design defects of the conventional drug delivery device, the present inventor has paid attention to the research and development according to the experience and the technology in manufacturing the associated products for many years, and thus developed this novel, convenient and utility drug delivery device to benefit the industry and the masses.